Package org.apache.flink.streaming.api.operators.source

Interface TimestampsAndWatermarks<T>

Type Parameters:

T - The type of the emitted records.

All Known Implementing Classes:

NoOpTimestampsAndWatermarks, ProgressiveTimestampsAndWatermarks

@Internal
public interface TimestampsAndWatermarks<T>

Basic interface for the timestamp extraction and watermark generation logic for the SourceReader.

Implementations of this class may or may not actually perform certain tasks, like watermark generation. For example, the batch-oriented implementation typically skips all watermark generation logic.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	TimestampsAndWatermarks.WatermarkUpdateListener	Lets the owner/creator of the output know about latest emitted watermark.

Method Summary

Modifier and Type	Method	Description
org.apache.flink.api.connector.source.ReaderOutput<T>	createMainOutput(PushingAsyncDataInput.DataOutput<T> output, TimestampsAndWatermarks.WatermarkUpdateListener watermarkCallback)	Creates the ReaderOutput for the source reader, than internally runs the timestamp extraction and watermark generation.
static <E> TimestampsAndWatermarks<E>	createNoOpEventTimeLogic(org.apache.flink.api.common.eventtime.WatermarkStrategy<E> watermarkStrategy, org.apache.flink.metrics.MetricGroup metrics)
static <E> TimestampsAndWatermarks<E>	createProgressiveEventTimeLogic(org.apache.flink.api.common.eventtime.WatermarkStrategy<E> watermarkStrategy, org.apache.flink.metrics.MetricGroup metrics, ProcessingTimeService timeService, long periodicWatermarkIntervalMillis)
void	startPeriodicWatermarkEmits()	Starts emitting periodic watermarks, if this implementation produces watermarks, and if periodic watermarks are configured.
void	stopPeriodicWatermarkEmits()	Stops emitting periodic watermarks.

Method Detail

createMainOutput

org.apache.flink.api.connector.source.ReaderOutput<T> createMainOutput(PushingAsyncDataInput.DataOutput<T> output,
                                                                       TimestampsAndWatermarks.WatermarkUpdateListener watermarkCallback)

Creates the ReaderOutput for the source reader, than internally runs the timestamp extraction and watermark generation.

startPeriodicWatermarkEmits

void startPeriodicWatermarkEmits()

Starts emitting periodic watermarks, if this implementation produces watermarks, and if periodic watermarks are configured.

Periodic watermarks are produced by periodically calling the WatermarkGenerator.onPeriodicEmit(WatermarkOutput) method of the underlying Watermark Generators.

stopPeriodicWatermarkEmits

void stopPeriodicWatermarkEmits()

Stops emitting periodic watermarks.

createProgressiveEventTimeLogic

static <E> TimestampsAndWatermarks<E> createProgressiveEventTimeLogic(org.apache.flink.api.common.eventtime.WatermarkStrategy<E> watermarkStrategy,
                                                                      org.apache.flink.metrics.MetricGroup metrics,
                                                                      ProcessingTimeService timeService,
                                                                      long periodicWatermarkIntervalMillis)

createNoOpEventTimeLogic

static <E> TimestampsAndWatermarks<E> createNoOpEventTimeLogic(org.apache.flink.api.common.eventtime.WatermarkStrategy<E> watermarkStrategy,
                                                               org.apache.flink.metrics.MetricGroup metrics)